Supply of air to an air-conditioning circuit of an aircraft cabin

Abstract

An aircraft turboprop engine has at least one low-pressure body and one high-pressure body. The low-pressure body drives a thrust propeller using a gearbox. The turboprop engine further includes a means for supplying air to an air-conditioning circuit of an aircraft cabin. The supply means includes a load compressor and a rotor that is coupled to the low-pressure body by the gearbox. The supply means further includes a means for controlling the rotation speed of the rotor of the compressor, which means comprise an electric motor, and a mechanical differential for coupling a first output shaft of said electric motor to a second output shaft of said gearbox and to said compressor rotor, such that the rotation speed of said rotor depends on the respective rotation speeds of said first and second output shafts.

The invention claimed is: 
     
       1. An aircraft turboprop engine, comprising at least one low-pressure body and one high-pressure body, the low-pressure body driving a thrust propeller by a gearbox, the turboprop engine further comprising means for supplying air to an air-conditioning circuit of an aircraft cabin, said supply means comprising a load compressor, a rotor of which is coupled to said low-pressure body via said gearbox,
 wherein said supply means further comprise means for controlling a rotation speed of the rotor of said compressor, which means comprise: 
 an electric motor; and 
 a mechanical differential for coupling a first output shaft of said electric motor to a second output shaft of said gearbox and to said compressor rotor, such that the rotation speed of said rotor depends on the respective rotation speeds of said first and second output shafts. 
 
     
     
       2. The aircraft turboprop engine according to  claim 1 , wherein said mechanical differential is integrated in said gearbox. 
     
     
       3. The aircraft turboprop engine according to  claim 2 , wherein said electric motor is integrated in said gearbox or is mounted on said gearbox. 
     
     
       4. The aircraft turboprop engine according to  claim 1 , wherein said control means comprise means for measuring the rotation speed of said second output shaft and means for controlling the rotation speed of said first shaft depending on a desired air flow for supplying said circuit. 
     
     
       5. The aircraft turboprop engine according to  claim 4 , wherein said control means comprise means for measuring the rotation speed of said first output shaft. 
     
     
       6. The aircraft turboprop engine according to  1 , wherein said differential comprises a central sun gear connected to said second output shaft or formed by said second output shaft, an outer ring that extends around the central sun gear and is connected to said first output shaft or formed by said first output shaft, and satellite gears that are respectively meshed with said central sun gear and said outer ring and that are supported by a satellite carrier connected to said rotor or forming said rotor. 
     
     
       7. A method for supplying air to an air-conditioning circuit of a cabin of an aircraft that is equipped with at least one turboprop engine according to  claim 1 , the method comprising at least one of the following steps:
 rotating said first shaft in a direction opposite that of said second shaft, such that the rotation speed of said rotor is less than that of said second shaft, during at least one operating phase of the turboprop engine; 
 rotating said first shaft in one direction, while the rotation speed of said second shaft is substantially zero, during at least one operating phase of the turboprop engine; and 
 not rotating said first shaft, the rotation speed of said second shaft imposing a rotation speed on said rotor, during at least one operating phase of the turboprop engine. 
 
     
     
       8. The method according to  claim 7 , wherein the step of rotating said first shaft in a direction opposite that of said second shaft is performed upon aircraft take-off. 
     
     
       9. The method according to  claim 7 , wherein the step of rotating said first shaft in one direction, while the rotation speed of said second shaft is substantially zero, is performed when the aircraft is in off mode or hotel mode. 
     
     
       10. The method according to  claim 7 , wherein the step of not rotating said first shaft, the rotation speed of said second shaft imposing a rotation speed on said rotor, is performed at idle power.